I use the Mini Hobby electronic sequencer in combination with two Robart/BV valves and mini servos. Easy to set up and very reliable. I also like the option of being able to physically move the valves independently (without the radio on) to open/close the doors and gear. Makes adjustments, transportaton, troubleshooting, etc. much easier.

Craig

http://www.minihobby.com/electronics/mhgdc.htm